Thermostat.



E. W. GOMFORT. THERMOSTAT. APPLICATION FILED JUNE 11, 1904.

912,287. Patented Feb. 16, 1909.

2 SHEETS-SHEET 1.

Wlzyvzissnsf v E. W.

comrom.

THERMOSTAT.

APPLICATION FILED JUNE 11, 1904.

Patented Feb. 16, 1909.

2 SHEETS-SHEET 2.

M R m T A //v VENTOR ,W 2d

' apartment, through which the hot and cold oi i icie PANY, OFClilUJ'LGO, ILLlliOiS, A CORPORATION.

Application filed June 11, 19042.

Specification of Letters Patent.

Patented Feb. 16, 1909.

Serial No. 212,122.

To all whom it may concern:

it known that. l, En'xvsiuo il COMFORT, 1cn oi: t United States,residing uti :1 or. no (lliiicugo, in the county oil Cook and State orIllinois, have invented new and useful lrnprovemcnts in TllBllHOSlifltS,of which the following is :l'ull, clear, concise, and exact description,reference being bad to the acctnnpony ing (.litlWlIlg, fornnng a pirt ofthis specification.

My invention relates to a 'iparetus for antonuiticully controlling thetemperature in buiidin and other places. 1

Qhe best results in controlling the tem pereturc in apartments have beenobtained through the medium of a mixture of hot and cold f udmitted tothe some and to attain such results it has been the general custom toerrenge passages 01" ducts leading to the air is admitted forcontrolling the to" perature of the same, end to control the z, 7

mission of air by dampers arranged in pa sages or ducts. 'ihese thunpersure pier rolled by motors operated supplied from toitro the 'liuid w sbe tlu d under pi e edri'ted to tl'ieinotors. A therino tic element edin the apartment is provided for lling the v ve. it has been found thatthe best lGSdlt for coiiitrolling the te1nltui'e are. obtained bygradually varying the relative proportions of hot and cold air athni"the apartment, as it sulden proportions of the mixture of i t. on, onlyadmitting one or the other at a time, produces too rapid u change in thetemperature and does not cf feet uniform, regulation.

It is therefore the oii ject of the present invention to provide athermostatic elen'ient which will control the motor and cause the someto gradually change the position o the dampers under the variations often:-

1 line 33 of Fig. s,

element, in which a tube A,

section taken on the line l l of Fig. in my preferred arrangement, asshown in Fig. l, the room 2 to be heated is provided with the registeror opening 3, which communicates, by means of a duct 7 for the admission01": hot and cold air into the room, with the cold air room 01' passagel, and with, the room 5, which is heated by the steam coil 6. The air inthe duct 7'is mixed in desired proportions of hot and cold air by the'dan'ipers' S and 9, suitably connected together, so'that as one closes,the other is opened and operated by the pressure motor 10, whichcontrolled by the thermostatic device 11 placed in the room 2, a sourceof fluid under pressure '12 being also connected with said device tofurnish power for the operation of the motor .10.

As will be apparent from an inspection of the figures, it is notdesirable, in ordinary temperature regulation, to entirely close eitherthe hot or cold air duct, for this would throw the hot 01' cold airalone into the room. An intermediate position of the dampers, so tosuitably temper the air introduced into the room, is, therefore,ordinarily desired, and it is for this method of Working that myinvention is especially advantageous.

in Figs. 2 to 4 is shown my thermostatic preferably of mid rnbber,but ofany material responsive to temperature changes, is provided. A plug B isscrewed into the lower end of the tube and is provided with a port Sleading to the open air. A second port G is formed in the side of aprojection B formed on the base oi the plug B, said port connecting withthe opening ll, to which is connected the pipe 16, leading from thesupply tank 1.2, a suitable tiller 1 being provided in the opening orport-ll, A casing T is preferably formed on the lower end of the plug B,this casing having an opening Y, through which the pipe 16 extends to beconnected with the port Extending from the upper end of the projection13, and. preferably supported thereby, is a support E, to which issecured a block M. In securing said block in position the same ispreferably formed with an opening therein, through which the upper endof the support E passes, and a pin F is then preferably driventransversely through the support B, and the block M. thereby seund Fig.1 is a. partial curely holding the block in position. Dc-

pending ti om the opposite end of said block 1 is preterably alint-spring N, to the lower end of which is secured the arm I), formingat its lower end a valve 1) for the port or opening Ur. becured to thespring at, at a point intermediate between the block M and the valve arm1), is an inwardly projecting block U, which has a seat U preterablytormed therein, immediately below an opening at in the block at. uponthe top of said block t, bears the lower end or a pm or rod it, which'13 prererably pointed and passes through the opening at, having its endseated in the recess 0. Upon the upper end oI said pin bears the pointor a screw J, which passes through a plug it, preferably threaded intothe upper end of the tube A. 1n,assenibl1ng the parts 01 the thermostat,the pin or rod ti, aliter being set upon the block L), is held 111 acentral position by a disk L, wlnch engages the inner walls ot the tubeuntil the sciew is brought to bear upon the top of said pin. 15y turningthe screw J, the position or the valve, relative to its seat, may beadjusted. Alter the screw has been set,

it is pret'erably covered by a cap or casing (t), threaded upon the plugH, to give the thermostat a finished appearance and to protect the screwJ.

As shown in Fig. 1, the source of supply 12 is connected directly withthe motor 10, by means of pipes 20 and 16. From an intermediate point ofsaid connection the single pipe lo leads to the thermostat 11, which, asbefore described, is placed in the room 2, the ten'iperature of which isto be controlled. In the pipe 20, between the branch leading to thethermostat, and the source of supply, a restricted passage 20- isprovided, said passage, as shown, consisting merely in a reduction indiameter of the pipe 20, but it is apparent that any other means forproducing the restricted passage may be employed, as, for instance, anadjustable valve. With this arrangement the pipe 16 is connecteddirectly with the interior of the thermostatic tube A, as, for instance,with the port R, while the other'opening S, is an outlet and opensdirectly to the atmosphere.

In operation, I will refer to the pressure of the tluid from the tank asthe supply pres sure and to this pressure at the port, reduced by whathas escaped through the valve, as the ell'ective pressure. It will benoted that there is a constant fluid pressure in the tank and when thevalve 1) is open, there is a constant flow of air through the restrictedpassage 20 to the thermostat and through the port S to the atmosphere.The normal position of the valve D is closed, being held in thatposition by the ten ion'ot the spring N, unless some means are providedto aid the pressure at the port G to flex the spring and low the valveopen; the tension of this spring being such that it requires more thanthe tall tank pressure to open the valve. The consequence of this isthat if it were not for the pressure of the thermostatic element ltransn'iitted through the rod K, the thermostatic valve or the valve 1)would remain permanently closed and the full pressure would always beexerted upon the diaphragm ot' the motor 10. The contraction ol. thethermostatic element under the inlluence ot' a low temperature producesa pres- :-:ure on the block C which neutralizes a part of the tension ofthe spring N and thus permits the fluid under pressure in the port to ablow the valve open. This opening of the valve and release of theflutdunder pressure reduces the pressure acting to blow the valve open andtlie'san'ie closes again until the supply through the restricted openingin the pipe restores pressure to a degree sullicient to again open thevalve. It will be noted from the above that there are only two forcesacting, namely, the fluid pressure tending to blow the valve open andthe spring pressure tending to hold the valve closed, the latter beingmodified by the thermostatic element.

For the purpose of illustration, it will be assumed, for instance, thatthe temperature ol the apartment in which the thermostat is placed, is69 i ahrenheit. Under this condition, the thermostatic tube will assumea definite length, and for this length of the tube the parts will assumea position wherein the valve, by remaining slightly open, or byrepeatedly opening and closing in rapid succession, will permit theescape of fluid from the storage chamber 12 at a rate equal to the rateat which it is supplied through the restricted passage 20 therebypreventing air passing either to or from the motor 10, and thusmaintaining a constant pressure in the motor. In this position, theellective flu id pressure (that is, the pressure at the port G) and thespring pressure are nicely balanced, the valve vibratii'ig slightly asone or the other predon'iinates, maintaining a constant pressure in themotor to thus hold the valve or damper controlled by the motor in adefinite position so long as the temperature in the apartment remains atthe assumed temperature of 6. l ahrenheit. Assuming now, that thetei'nperature increases to, say, 70, the thcrn'iost atic tube willexpand graduall thereby relieving somewhat the pressure on the block (7and permitting the spring N to act with greater t orcc and more theval'.'c toward its seat. This prevents the fluid 'escapii'ig a rapidlyas it" passes through the restricted pa c '20". and the pressure in themotor will be increased. causing the lat ter to operate to cto e the hotair damper 9 and open the cold air damper The pressure at the port (2will." however, oppose the tension of the spring to such an extent thatabove, but these thermostats areas? the spring pressure will againbalance. This nice balancing of thcspring pressure and the fluidpressure maintainsthe pressure in the motor practic-ally constant-,1 andthe damper or valve thus remains in a definite position so long as thetemperature remains at the assumed This balancing effect of theeffective pressure and the spring pressure may result in the valveremaining partially open, or it may result in a repeated opening andclosing of the valve in quick succession, but in either case thepressure at the-motor will be maintained practically constant for agiven temperature. Likewise, when the temperature falls again to, say,69,the thermostatic tube,

contracting, decreases the pressure of the valve D on the port G, whichallows the fluid to again readily esca pe through the port Gr, therebypermitting a greater amount of fluid to escape to the atmosphere throughthe pipe 1.6 and 16, than will pass through the restriction 90 in thesupply pipe 20, until the spring and the effective fluid pressures againbalance, when" the decreased pressure in the motor will be maintainedconstant to hold the damper in a new definite position so long as thetemperature remains constant. It will thus be noted that the heatresponsive ele' ment of the thermostat serves to vary the tension of thespring N and therefore to modify the force with which it presses thevalve against its seat, so that the valve, instead of following theprecise movement of the thermostatic element, partakes or a retardedmovement, due to the tension of the balancing spring, which prevents thevalve from moving in a direction to open or elose the port as rapidly aswould be the case were the valve connected directly and unyieldingly tothe thermostatic element.

In previous patents granted to me I have v hown devices for a similarpurpose, as have worked on the principle of a pressure reducing valvethermostatically adjusted. The present de vice, itv will be noted, onthe contrary, is a safety valve thermostatically adjusted. Thethermostatic element sets the safety valve so thatit may be opened atany desired pressure up to the full pressure of the fiuid supply.

F or the purpose of illustration, 1 have shown my thermostat as appliedto one syslem of apparatus for controlling the temperature ofapartments, but it is apparent that .it is applicable to other systemsand I do not wish to limit myself to the particular form shown in thepresent application. as the same may be used for controlling valves andfor various other purposes.'which it has been thought unneces ary toil.1strate.

I have shown in the drawings the thermostatic elementas being a tube in"which the valve and other operative parts are in- I which and theedective pressure l closed, but it will be understood that I do not wishto limit myselfto this specific form of thermostatic element as anyother thermostat may be provided for producing the same result and it isnot necessary that the operative parts should be inclosed, as shown, butthe same may be left entirely open and subjected to the influences ofany thermostatic element, which it may be desirable to use.

lWien speaking of a valve in the claims, I contemplate not only a singlevalve, but

also any valve combination or valve mechanism capable of accomplishingsubstantially similar results.

Having described my invention what I claim as new and desire to secureby Letters Patent is:

1. The combination with means for conveying a fluid under pressure, of avalve for governing the flow of said fluid, said valve.

closing in a direction opposite to that of the flow of the fluid andbeing under the influence of the pressure of said fluid passing throughsaid valve, and 'yieldable means tending to hold said valve closed, thetension of said yieldable means being under thermostatic control, tovary the force exerted thereby.

2. The combination with a thermostat constituting a hollow chamber, of afluidsupply, a motor operated by fluid from said supply, a valve forgoverning the flow of the fluid, said valve closing in a directionopposite to that of the flow of the fluid and being under the influenceof the pressure of said fluid, and yieldable means within said chambertending to hold said valve closed, the tension of said yieldable meansbeing under the control of, and varied by, said thermostat.

3. In combination, a source of fluid pres sure, a motor actuated by thefluid, an inlet pipe extending directly between said fluid supply andsaid motor, a thermostat, a pipe extending from said motor to saidthermostat, a valve controlling the pressure to the motor is subjected,said valve closing in a direction opposite to that of the flow of thefluid and being under the influence of the pressure of said fluid, saidvalve controlling the escape from the motor, yieldable means tending tohold said valve closed, the tension of said yieldable means being underthe control of said thermostat, said inlet pipe having at one point arestriction which is of less area than the exit controlled by the valve.

a. In combination, a source of fluid pressure, a motor actuated by thefluid, an inlet pipe extending directly between said fluid supply andsaid motor, a thermostat, a pipe extending; from said motor to saidthermostat, a valve controlling the pressure to which the motor issuojeeted and being under the influence of the pressure of said fluid,said valve controlling the eseapettrom the motor, yieldable meanstending to hold said valve closed, the tension of said yield able meansbeing under the control of said thermostat, said inlet pipe having atone point a I'GStLlCtlOll which is of less area than the exit controlledby the valve.

5. lhe combination of a source of supply of fluid under pressure, amotor having a vent, means tor,conductingdlnid from said source to saidmotor, nieans tor limiting the flow through said conducting means, and

means for controlling the escape of fluid from said vent, said meanscomprising a valve tending to close said vent against the flowtherefrom, and a thermostatic element arranged to gradually vary theforce with which said valve acts to close said vent.

6. The combination with a thcrinostatii':

tube of a lon itudiiiall arran ed sai wit 7 a a l 7. The con'ibinationwith a source of fluid -1 supply, of a motor provided with a vent,

means for conducting fluid from said source to said motor, said meansbeing arranged to limit the flow therethrough, and means for controllingthe escape of fluid from said vent and thereby varying the relationbetween the flow through said conducting means and the flow from saidvent, said means comprising a valve, a spring tending to close saidvalve against the flow from the vent, and a thermostatic elementarranged to vary the power of said spring.

The combination of a source of fluid supply, a motor, means i'orconducting fluid from said source to said motor, and means for varyingthe pressure in said motor, said means coni 'irising a thermostaticelement having a chamber therein con'ununicating with the atmosphere andhaving a port cominiiiiicating with said motor, a valve in said chamber,and an energy storage device tendingto close said valve against the flowof fluid it'i-ma said port, the power exerted by Hai i encr' 'v stoiagedevice being varied by the expansion and crnitraction ofsaiditherlliOFt;:il(f ttltl3i(llt.

Iln witness whereof, I have hereunto subscribed by name in the presenceof two witnesses.

EDWARD W. COMFORTf Vitnesses:

W. Pnnnr Hal-1N, E. R. Kine.

